CNC music factory Still Alive

With some careful programming and probably tedious testing, [Tim] was able to get his CNC router to play [Jonathan Coulton’s] “Still Alive”. He didn’t just tell the motors to spin at the correct speeds directly though. He computed the 3d vectors necessary to produce the notes. The router thinks it is just doing its job. We would love to see those vectors rendered out in 3d space. Imagine having a physical sculpture of “Still Alive” as seen by a CNC machine. This reminds us of the Obsolete Technology Band.

Hah, yeah i’ve been wanting to do a 3D song thing for a while with our CNC, but i have no idea where to even start. It would most likely just dull a good tool from the varying RPM’s. I’m sure i could find a bad tool with mostly good edges, but still, anyone have any ideas on how to start?

Also, WTF is actually happening in the video? i can’t even see any cutting going on.
-Taylor

Taylor> It’s not cutting at all, it’s the stepper motors stepping at different speeds which is generating the tones. It’s using X and Y as two different voices. I didn’t see if the router was going up and down so there might have a 3rd Z voice.

IIRC at least one model of HP ScanJet understood SCSI command that would play arbitrary notes with the scan head drive motor. There was some tune that it would play out of ROM if you held on the scan button while powering it on as well.

@sean: The song is mostly 2-note, but there are a few places where it busts into a full 3-note harmony. Still Alive was a very good first test since it never has more than 3 notes on at any given time. I’d like to play ‘Don’t Fear The Reaper’, but it’s too complex to sound good on a 3-axis machine :)